The present invention generally pertains to multi-speed transmissions for motor vehicles. More particular, the present invention pertains to a reverse gear assembly for motor vehicle multi-speed transmissions. More specifically, but without restriction to the particular embodiment and/or use which is shown and described for purposes of illustration, the present invention is directed to a reverse gear assembly for a manual transmission having a sliding reverse idler. The reverse gear arrangement is provided with enhanced tooth pointing for reducing shift effort.
As is well known, shifting gears in manual transmissions is caused by selectively coupling one of the gearsets for driving the output shaft at a predetermined speed ratio relative to the input shaft. Most manual transmissions include a plurality of synchro-mesh gearsets for establishing the forward gears. Sliding-type gearsets have traditionally been used for establishing the reverse gear. Modernly, manual transmissions are often equipped with synchronized reverse gear arrangements for preventing the undesirable grinding noise often associated with conventional sliding-type arrangements. An exemplary synchronized reverse gear arrangement is disclosed in commonly assigned U.S. Pat. No. 5,722,291, which is incorporated by reference as if fully set forth herein.
While known reverse gear arrangements generally perform their intended function, all are associated with disadvantages. For example, as a reverse gear assembly translates a reverse idler to ultimately achieve idler gear tooth meshing with input and output shafts, the idler must first index into the proper orientation to allow its gear teeth to pass into both the input and output gear tooth space widths. Known arrangements incorporating a pointed spur tooth sliding idler reverse system often encounter centerline crossing of idler to output sleeve tooth pointing. Such centerline crossing leads to blockout and increased shift effort. Additionally, synchronized reverse gear arrangements are associated with increase costs.